The tunnel has been closed for traffic for now.
A massive chunk of flyover in Himachal Pradesh's Solan collapsed on Thursday as heavy rain and cloudbursts caused landslides across the state.
Videos show two vehicles were hit when the flyover caved in; no casualties have been reported so far, according to local reports.
The flyover connects the four-lane tunnel on Kalka-Shimla National Highway-5, and usually sees heavy traffic. The tunnel has been closed for traffic for now.
"There's been massive rain in Himachal since last night. All deputy commissioners have been put on alert to report about the damages. There have been infrastructure losses in Kullu and Mandi areas," said Chief Minister Jai Ram Thakur.
Earlier on Thursday, in Kullu, Chavelu Devi (55) and Kritika (17) died when their house at Khadel in Anni subdivision was hit by debris following a landslide around 9 am, said Sudesh Mokhta, director of the state disaster management department.
In Deuthi village in the same area, 10 shops and three vehicles were washed away following a cloudburst and flash floods earlier this morning, around 7.30 am. An old bus stand and a panchayat building are also facing the risk of being washed away in the village.
The national highway to Kullu from Mandi was blocked, too, following a landslide near Pandoh in the morning. Traffic has been diverted through Kataula.
At Bharmour in Chamba, the Hindu pilgrimage of Manimahesh was halted due to flashfloods caused by a cloudburst - videos of which went viral - the second time in a week.